1. Field of the Invention
The present invention relates to a processing method based on resist pattern formation and having a step of forming a pattern on the surface of a processing target member with a resist film, and a step of processing the processing target member based on the presence/absence of the pattern on the surface of the processing target member by causing a non-patterned portion to be changed by processing while protecting a patterned portion from being processed, and a resist pattern forming apparatus for forming the resist pattern.
2. Description of the Related Art
A processing method is known wherein a pattern is formed on the surface of a processing target member with a resist film, and processing is performed based on the presence/absence of the pattern on the surface of the processing target member by causing a non-patterned portion to be changed by processing while protecting a patterned portion from being processed.
As the application fields of this processing method, pattern etching, pattern plating, pattern vapor deposition, pattern electrolytic oxidization and the like are known and are widely practiced. In particular, etching is employed for processing a printed circuit board member and forming a hole or holes in a thin plate, and is thus regarded to be very important.
An example of this known etching method will be described below with reference to FIG. 26.
A base material, e.g., various types of metals, polyimide, or the like, which can be dissolved by an etchant is prepared. This base material is subjected to a cleaning step 201 for degreasing or the like, and is then subjected to a baking step 202 for removing water adsorbed in the base material.
Subsequently, a resist forming step 203 is performed. In this resist forming step, a liquid resist agent is coated on the base material, or a resist film formed in advance is bonded to the base material. In a pre-baking step 204, the solvent of the resist is removed by evaporation.
A pattern for etching is formed in a pattern designing step 205 by using a CAD (Computer Aided Design) or the like. The designed pattern is plotted in a plotting step 206 with a cutting plotter or a photoplotter, and is checked. At this stage, the pattern is plotted out with a larger magnification than the size of a pattern which is ordinarily processed. The plotted-out pattern is then photographed with a camera in a film photographing step 207. The photographed film is developed to form an exposure original. In an exposing step 208, the exposure original is placed on the surface of the pre-baked base material, and the base material is exposed to ultraviolet radiation through the original.
In the pattern of the exposure original, a portion that should remain after etching is transparent, and a portion that should be removed is black. When ultraviolet exposure is performed through this exposure original, a portion of the resist on the base material corresponding to the transparent portion of the pattern is polymerized and set with the ultraviolet rays. Accordingly, when the resist is polymerized and set with the ultraviolet rays, exposure is ended. After exposure, a developing step 209 for removing a non-set resist material is performed. The developing agent and a rinsing solution are evaporated in a post-baking step 210. The adhesion force of the set portion is increased by heat, thus ending resist pattern forming steps.
When the resist is patterned in this manner, the flow advances to an etching step 211. In the base material etching step 211, a solution that chemically dissolves a metal, e.g., ferric chloride, cupric chloride, or the like, is caused to act on the patterned surface, thereby removing the metal at a portion of the base material where the resist pattern does not exist. In the final resist removing step 212, the resist film which is no longer necessary is removed by peeling or oxidization, thus ending the entire process.
The units that are used in the resist pattern forming steps are a cleaning tank, a baking furnace, a resist coating machine or a resist bonding machine, an ultraviolet exposure unit, a resist developing unit, a CAD, a cutting plotter or a photoplotter, a large-sized camera, a set of film developing units, and a discharge water treating unit.
As the materials, a washing solution, a resist material, a cutting film, a photographic film, a set of photographic developing solutions, a discharge water treating agent, and the like are used.
The conventional etching method and apparatus described above have the following problems.
The conventional method requires a human resource having professional knowledge and skills for the operation. In processing, expensive materials are consumed for pattern formation. Moreover, a waste liquid and waste that may pollute the environment are produced, and an extra energy and water are consumed for processing. These problems must be solved.
The apparatus used in conventional resist pattern formation requires many types of expensive equipment for processing. Since the processing equipment occupies a large area, the facility investment is very large, and maintenance and management of the facilities require a high cost.
When a printed circuit board member is to be formed, in addition to formation of a conductive wire pattern, parts mounting is performed, parts names serving as the indices for later repairs, and patterns indicating parts mounting positions, parts postures, and the like are printed. For this purpose, a silk screen printing technique is employed. As is known, silk screen printing also requires formation of an original film, as in resist pattern formation, and includes complicated steps such as formation of an original plate, printing of the original plate with ultraviolet rays, and development. Character printing on the printed circuit board member is not finished until a printing step is performed by using a printing plate which is formed in this manner. Therefore, this printing process is more complicated and has more problems than conventional resist pattern formation, in addition to the various problems described above that accompany conventional resist pattern formation.
Furthermore, in formation of a printed circuit board member and the like, it takes time to form a film used for etching. If an error is found in the film when checking the formed film, a correct film must be formed, leading to a large loss in time and cost.
To form a large amount of flexible printed circuit board members, a resist pattern is printed on the board material unrolled from a rolled state in accordance with the silk screen printing technique, and the printed resist pattern is etched. Although this method is suitable for a mass production, it takes too much time for fabrication of an article sample on an experimental basis or the small-lot manufacture, leading to a high cost.
The conventional target of processing utilizing a resist pattern includes printed circuit board members. However, the conventional processing method has drawbacks as described above. In addition, the printed circuit board members are adapted in various types of equipment. A variety of requests are made for the manufacture of the printed circuit board members, ranging widely from a very small-quantity manufacture as in the manufacture on an experimental, trial basis, a small-quantity manufacture for application to a special exclusive equipment, to a large-quantity manufacture in a mass production for application to commercial products.
The conventional resist pattern forming apparatus for printed circuit board members has separate single-function units for different steps, as is apparent from the conventional processing method shown in FIG. 26. Manual operations are performed between the respective steps. Intermediate products exist, such as a circuit pattern film, an etching resist coating board material, and the like, and a preparation time and a storage space are required for formation of these intermediate products.
Therefore, the conventional resist pattern forming apparatus is not suitable at all for small-quantity pattern formation, e.g., quick manufacture of articles on the experimental basis in which pattern correction is often performed. When the small-quantity manufacture is performed intermittently, the original film must be stored. Since a frequent manufacture leads to a high cost, a large amount of printed circuit board members must be stored.